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Printer Prints but Won't Scan? Two Windows Services Are Usually Why

By Justin · Woodstock Computer Repair · 2026-08-27 · Updated 2026-10-26

A customer called about a Brother all-in-one that had stopped scanning. Printing still worked perfectly. Same printer, same cable, same network, same computer, and one half of the machine had simply quit.

That split is the most useful diagnostic you have, because printing and scanning do not travel the same road. When one works and the other does not, the printer is almost certainly fine.

Why one works without the other

Printing is a one-way trip. Your computer sends a job to the print spooler, the spooler hands it to the printer, done. Windows will even install a basic print driver for most printers automatically, without you doing anything.

Scanning is the opposite direction and a different mechanism entirely. Your computer has to find the scanner, open a channel to it, and pull data back. That depends on device discovery, on scan software that Windows does not install for you, and on the firewall allowing the return traffic.

So the common outcome is a printer that prints beautifully out of the box and can never scan, and the owner assumes the scanner is broken.

The two services almost nobody knows about

Windows runs two background services that network scanning leans on:

• Function Discovery Provider Host
• Function Discovery Resource Publication

Between them they let your PC find devices on the network and announce itself to them. If either is stopped or set to Manual, scanning breaks while printing carries on completely unaffected.

They get switched off in a few ordinary ways: a "speed up Windows" tune-up guide that recommends disabling services, some optimizer utilities, and occasionally a Windows update or a new user profile that leaves them not running. On this machine both were off, which is exactly what killed the scanner.

The fix is to set both back to start automatically and start them. That alone brings scanning back on a lot of machines.

The other half: the driver you did not install

The basic driver Windows gives you is a print driver. Scan-to-PC, the scan button on the printer itself, and the manufacturer's scanning app all come from the full software package from Brother, HP, Canon, or Epson.

If you have never deliberately installed that package, you do not have it, no matter how well the printer prints. On this job the full Brother software had never been installed, so even with the services fixed there was nothing on the PC to receive a scan.

Get that package from the manufacturer's own support site, using your exact model number. Not a driver aggregator site, not a "driver updater" tool. Those are a common way to end up with bundled adware instead of a working scanner.

The computer sees the printer but not the scanner

This is the same split from the computer’s side, and it is the version most people search for: the printer is listed, jobs print, and no scanner shows up anywhere. Windows set up the printer half on its own and nobody ever set up the scanner half.

• Look where Windows keeps scanners. Settings, then Bluetooth & devices, then Printers & scanners. If your all-in-one appears only as a printer and nothing will scan, the scan side was never installed.
• Add it the way Microsoft describes. On that same page, choose Add device next to Add printer or scanner and give the search a few minutes. If it never appears, Microsoft’s scanner help page points to The printer that I want isn’t listed, and to the scanner maker’s site.
• Check the network name. For a wireless all-in-one, the computer and the printer have to be on the same WiFi network. A laptop on the guest network, or on an extender with its own network name, will not find a scanner sitting on the main one.
• Install the full package. The maker’s full driver and software for your exact model is what adds the scanner. Once it is in, the scanner usually shows up in Device Manager under Imaging devices, and the maker’s scan app can find it.

If the scanner was found once and has since disappeared, go back to the two services above. That pattern, working for months and then gone after a tune-up or an update, is the one they cause.

Which scan program your printer actually needs

The question I get most after “why won’t it scan” is “what do I even open to scan.” Each maker has its own program, and each one comes from the maker’s site, not from a search result.

• HP: the HP app, which HP says replaced the HP Smart app and works as both the printer and the scanner app on Windows. If an older HP Smart is still on the machine, that is the one to update.
• Canon: IJ Scan Utility, which comes inside the driver package for your model rather than as a separate download.
• Epson: Epson ScanSmart. On Windows 11 search for it from the Start button; on Windows 10 it sits under Epson Software in the Start menu.
• Brother: Brother iPrint&Scan, with a Windows download on Brother’s site. This was the piece missing on the job above.
• Any brand, in a pinch: the free Windows Scan app from the Microsoft Store. It uses whatever scanner driver is installed and saves to the Pictures folder under Scans. If Windows Scan can see the scanner and the maker’s app cannot, the maker’s software needs reinstalling. If neither can see it, go back to the two services and the network.

Scans from the computer but not from the button on the printer

This one confuses people because the scanner is obviously working. Scanning started at the computer only needs the driver. The scan button on the printer works the other way: the printer has to know which computer to send to, and that computer has to have the maker’s software running in the background to receive it. On every brand above, that “scan to PC” registration lives in the maker’s program, and it is lost when the software was never installed, when the computer was replaced, or when the printer got a new network address. Re-run the setup in the maker’s app with the computer on and awake, then test from the printer’s panel again.

Then the firewall

Scanning pulls data back to your computer, which means the firewall has to permit it. After installing the software, the scanning application needs to be allowed through Windows Defender Firewall on your private network. This is the last piece that catches people who did everything else right.

The order to work through

• Confirm the printer still prints, which proves it is powered, connected, and healthy
• Set both Function Discovery services to Automatic and start them
• Install the manufacturer's full driver and scan software for your exact model
• Allow the scan software through the firewall on the private network
• Test Scan to PC from the printer's own panel, not just from the computer

That last test matters. Scanning initiated at the printer uses a slightly different path than scanning started on the PC, and it is the one people actually use day to day.

When it is not the computer at all

If none of that works, look at the network. On a shared or misconfigured network, devices can be blocked from finding each other entirely, which breaks scanning, casting, and smart devices all at once. Two situations to know about: apartment and community WiFi, where the building controls it, and a home network left misconfigured after an internet install, where you can simply turn it off.

A printer that prints but will not scan is a software problem far more often than a hardware one. Printer and WiFi setup is a common house call, and it is usually a short one. The pricing page shows how a visit works.

Questions people ask

Why can my printer print but not scan?

Scanning depends on device discovery and scan software Windows does not install automatically. Printing does not. One works, the other silently fails.

Which Windows services does network scanning need?

Function Discovery Provider Host and Function Discovery Resource Publication, both set to Automatic and running.

Do I need the manufacturer's software to scan?

Usually yes for full features. Windows installs a print driver on its own but not the scan side.

What program do I use to scan on Windows?

The maker's own app: the HP app for HP, IJ Scan Utility for Canon, Epson ScanSmart for Epson, and Brother iPrint&Scan for Brother. The free Windows Scan app from the Microsoft Store works with any installed scanner driver as a fallback.

Why does my printer scan from the computer but not from the scan button?

The scan button needs the printer to know which computer to send to, and that computer needs the maker's software running to receive it. Re-run the scan-to-PC setup in the maker's app with the computer awake, then test from the printer's panel.

Why does my computer see the printer but not the scanner?

Windows set up only the print half of the all-in-one. Install the maker's full driver and software for your exact model, check that the computer and printer are on the same WiFi network, then add the scanner under Printers & scanners in Settings.